| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunnel excavator capable of excavating a gallery of high strength. SOLUTION: This tunnel excavator 1 has a plurality of rotary cutters 11, 11 provided at the front of an excavator main body with a predetermined horizontal interval between the cutters 11, 11, and is provided with a trimming cutter 10 for excavating the roof part of a gallery into an arcuate shape. Since the roof part of the gallery is excavated into an arcuate shape by the trimming cutter 10, the gallery itself becomes resistant to load so as to reduce the possibility that the roof part may collapse. |
